The present invention relates to a side airbag device for restraining an occupant's head having an airbag which is deployed at an upper side portion in a vehicle cabin to protect the head of the occupant in the event of a vehicle collision, and more particularly, to a side airbag device for restraining an occupant's head having a cover with improved strength and capable of providing easy installation.
In the airbag devices installed in vehicles, there is an airbag device such that a pressure or impact applied at a vehicle side is detected so as to inflate an airbag thereof at an upper side of a vehicle cabin. The head of an occupant is restrained or supported by this airbag to absorb kinetic energy for protecting the head of the occupant. Such an airbag device is called "a side airbag device for restraining an occupant's head" or "side impact airbag device (hereinafter, sometimes referred to as only the "side airbag device"). Most of the side airbag devices of this kind are installed along a roof side from a front pillar to a center pillar.
A side airbag device of this kind comprises a casing for accommodating an airbag therein. The casing is made of a thin member, which can be easily formed, such as soft iron, aluminum, or synthetic resin, and has a mounting portion to be fixed to a vehicle body. Inside the casing, an airbag body (abbreviated to as "airbag") is accommodated in the folded state. The airbag is formed in a long envelop-like configuration such that its width direction is parallel to the vertical direction of the vehicle body and the longitudinal direction extends from a front pillar to a center pillar of the vehicle body.
The airbag is folded and accommodated in the casing in a normal state. In the event of a collision at the vehicle side, gas is supplied into the airbag from an inflator communicating with the airbag, so that the airbag is inflated to project outside the casing. During this process, the airbag pushes the casing from the inside to tear or deform the casing to open it. The airbag projecting from the casing is deployed into a predetermined configuration between the vehicle body and the head of the occupant. Therefore, the kinetic energy of the head of the occupant caused by the side collision can be absorbed by the airbag.
However, since the conventional side airbag device as mentioned above is installed along the roof side, the space for installing the side airbag device is narrow and the side airbag device should have a complex configuration. There is therefore a disadvantage in taking a lot of time to install the side airbag device to the vehicle body.
The present invention obviates the above-described problem and the object of this invention is to provide a side airbag device for restraining an occupant's head which accomplishes the easy installation to a vehicle body and which can be manufactured at a low cost.